Bioaugmentation-Driven In Situ Rice Stubble Degradation: A Sustainable Strategy for Mitigating Greenhouse Gas Emissions from Paddy Soils

The intensification of rice cultivation has made sustainable stubble management challenging due to the short interval between harvest and the subsequent crop. This investigation evaluated accelerated in situ rice stubble decomposition and its effects on nutrient availability, greenhouse gas (GHG) emissions, and crop performance. Stubble decomposition was conducted for 45 days with nitrogen supplementation (urea), a biomineralizer, and rotavator incorporation. Among the treatments, stubble, incorporated with a rotavator, a biomineralizer, and urea (S rbu ), achieved rapid decomposition, reducing the C/N ratio from 61.7:1 to 23:1 within 45 days. During succeeding rice cultivation, S rbu significantly increased the available nitrogen (79.75–115.04%), available phosphorus (9.26–9.69%), and available potassium (121.02–153.85%) across growth stages, resulting in increased productive tillers, photosynthetic rates, and grain yield (10%), while reducing CH 4 and CO 2 emissions. DeNitrification-DeComposition (DNDC) model simulations further projected a 10-year decline in methane emissions under S rbu, highlighting its potential as a climate-smart rice stubble management approach.